Motivated by high quality multimedia and remote collaborative environments, we solve the problem of multigroup multicast routing with a~number of features important for real-world deployment of the interactive media technologies. Based on the ant colony optimization metaheuristic, our algorithm is the first to work with uncertain knowledge of underlying network capabilities and support on-the-fly media transcoding inside the multicast tree. New contributions of this work are described next. We present two extensions of the algorithm, which improve quality of the solution. We introduce an~integrated approach to solution of the problem, which is effective for both original solving from scratch as well as for new dynamic reconfiguration of multicast tree, where minimum perturbation of existing solution is desired. Experiments show that our algorithm is not only successful in maintaining existing communication with low number of unnecessary disruptions, but also capable of keeping the multicast trees efficient.